Green finance has become an important component in promoting the implementation of the “Double Carbon”strategy. Taking the marine economic circle as the research object, digital economy as the intermediary variable, and R&D investment intensity as the moderating variable, this study explores the impact of green finance on carbon emissions. The data from 2005 to 2021 were selected, and the fixed effect, mediating effect and moderating effect models were used for analysis, and the tail shrinking treatment was used for robustness analysis. The results indicate that Green Finance in the Marine Economic Circle can suppress carbon emissions, and the digital economy plays a mediating role, but the intensity of R&D investment has not clearly played a regulatory role.In view of this,should continue to promote green finance, improve the digital economy system and mechanism, and implement R&D investment.